Method of making bearings



Oct .19, 1937. H. l.. BROWNBACK METHOD OF MAKING BEARINGS Filed July 5y, 1935 6 Y /w//////H-////////////// @a A L 3. s w F KW H La J q u g .M/ 7,. f v 3 .w .w o F m 1 1 .1 1,1 V. fu \\v /l/n/ [Jv/I' /J//cI/d d//wlq J/ m.\ :E w` a v p w, w 7 J 3 2 2 1 3 1.

Patented Oct. '19, 1937 UNITED STATES PATE-:NT "OFFICE 4 Claims.

This invention relates primarily to bearings particularly for use in gasoline and other internal p combustion engines, and the principal object thereof is to provide a Vnovel bearing and method 5 of making same, the bearing consisting of lining steel or ferrous shells with bronze, copper, copper-lead mixtures, or brass, my novel method involving a step in which the molten copper of the .bronze or brass (or a molten copper illm alone) l'ls permitted to soak into the heated steel or ferrous shell for a sumcient length of time to lpermit penetration thereof an appreciable distance into the steel shell and to. form on the shell .a surface copper-iron alloy bonded with l the steel, to which alloy the bronze or brass which forms the material of the bearing lining will subsequently readily unite, thereby providing a novel bearing having a decidedly better bond between the shell and lining, the lining in fact having 20 penetrated and alloyed with the surface of the steel shell in much the same manner as carbon in case-hardening processes.

Another object of the invention is to provide a novel method of case-hardening the exterior 25 of the steel shell simultaneously with the depositing of the lining within the shell.

A still further object is to provide, a bearing in which the `lead constituent of the lining presents a spheroid structure rather than a crystal- 30 line structure in the ilnished lining, and can carry a much greater load.

In most cases the lining of steel shells with bronzes or brasses and particularly copper-lead mixtures high in lead has heretofore been ac- 35 complished by heating the steel shell in a nonoxidizing atmosphere to a temperature considerably higher than the melting point of the bronze, and`by heating the bronze to a temperature higher than its normal melting point,I and then 40 removing the vsliell from the furnace, adding av iiux, and pouring the bronzein the shell. As soon as this is done the piece is cooled quickly or quenched to avoid precipitation of the lead. Asthe copper of the lining is in contact with the 45 steel for only a short time interval the penetration is very slight, and moreover the copper has a tendency to oxidize during pouring. The ux, if used in excess, also causes trouble.

Another lprocess heretofore used consisted of y 50 putting bronze in a shell which was sealed at ture instead of having them in contact -for a de.- nite period of time at the ideal bonding temperature as the shell was necessarily quenched just as soon as the bronze was distributed as otherwise the lead would be also centrifuged into contact with the steel shell destroying the bond.

` This process was limited to the use of alloys fairly low in lead for the reason stated.

In my process the bronze or brass and the shell is preferably placed in a crucible ofthe type shown inA my French Patent No. 747,334, sealed The crucible, containing the shell and lining material, is heated at a temperature of about a 1975 to 2000L F. for a length of time suillcient to melt the bronze, brass;l or other copper alloy or mixture, and the crucible then turned or rolled slowly for a suilicient period of time to bring the molten brass," bronze or copper mixture in contact with the walls of the heated steel shell for an appreciable period of time, varying approximately from 3 to 6 minutes, allowing the copper to soak into thel steel, for an appreciable distance to form a surface copper-iron alloy forming a bonding medium, and a coating of copper adhering to the surface of the copper-iron alloy. Thel copper is found to have penetratedinto the steel in somewhat the 'same'manner as carbon in case-hardening processes. Afterwards, the crucible is removed from the furnace and agitated f thoroughly by shaking, rolling, or otherwise, to

mix the constituents of the brass, bronze, or lead vcopper mixture (which latter is a mechanical emulsion and not a true alloy) to break up finely and thoroughly mix the various constituents of the mixture. y In the case of crucibles in which the brass or bronze descends by gravity, the crucible subsequently is up-ended and plunged into water or other cooling medium so as to iix.

the brass or bronze and also to anneal the copper content; or in case the brass or bronze is to be centrifuged in. place, the crucible is put in a centrifuging machine, and as Asoon as the mixture is centrifuged, the crucible is quickly chilled to prevent the heavy portions of the mixture being displaced and to anneal the copper constituent.

The main feature of my process is the soaking of the copper into the steel for a denitely long period of time at an ideal temperature instead of the short periods employed in the other processes, for I have found that if the copper is not in intimate contact at the necessary temperature for the necessary time period for forming this alloy the bonding is faulty, i. e., not deep enough.

I will explain the invention with reference to y the accompanying dra'wing which illustratesseveral practical embodiments thereof to enable others familiar withthe art to adopt and use the same; and will summarize in the claims the essential features of the invention, and novel features of construction for which protection is desired.

vIn said drawing:-

Fig. 1 is a vertical section through a crucible for coating a shell interlorly only.

Fig. 2 is a similar section showing the crucible up-ended as when being heated.

Fig. 3 is a vertical section through the crucible showing a steel shell therein for coating both interiorly and exteriorly.r

In- Figa 1 the shell 1 is to be coated on its interior only, and the shell itself forms the outer casing of the crucible. In Fig, 1 the steel or other piece to be coated is designated by the reference character I, and is in the form of a tubular shellL lprinciples underlying the bearing are the same in both cases, and the vprocess'of manufacture is as follows:

The steel shell I of the bearing is lprepared and is carefully cleaned, preferably by pickling. After this the lower end of the shell I is hermetically sealed by a plate 2. The shell is then passed through a copper sulphate bath and copper deposited either naturally or electrolytically on the shell. A central core 3 is placed in the shell I and is passed through an opening in the plate 2, the coreA being welded as at 3a or otherwise secured to the plate 2 to form a gas tight joint. Core 3 extends somewhat beyond the opposite end of the shell I, and its extended end is closed by a disk 4 when a tubular core is used which is welded as at 4m or otherwise secured to cora 3, and this disk 4 is drilled with a very small escape hole 5 I theuse of which will be explained later. 'Ihis core 3 is only used in the case of gravity cast bearings, and in this case a container 6 which acts as a metal reservoir is hermetically secured to the shell at the end opposite the plate`2, and

qcontainer 6 is closed at its outer end by a plate At this point a volatile flux 8 such as salycylic I acid is introduced into the shell through opening 'la in suilicient quantity to, displace the air when the bearing is heated and maintain a non-oxidizing atmosphere in the bearing. The bearing metal 9 such as lead copper mixture or lead bronze or other bronze or brass alloy is put into the reservoir 6 through the opening 'la and the cover hermetically sealed. All the above operations are performed while the shell and parts are cold.

The crucible thus formed is preferably upended so that the reservoir 6 is lowermost, as illustrated in Fig. 2, and is then charged into a place the nuximaterial s put :nto the sneu von.- tilizes and displaces the air which escapes through the small orifice 5 in the inner end of the Acore I andpasses into the furnace. In case a furnace having a controlled atmosphere is used. the vol- `'atilizable flux A8 will iot have to be put in the shell as the heat will cause the air to expand and the controlled atmosphere in the furnace will displace the'air in the bearing.

After the crucible and the alloy metal 9 contained therein has reached the above desired temperature, part of the lead will flow from the lead bronze and will collect in the bottom ofjthe reser- `voir 6 (Fig. 2); also'the thin coating of copper copper vsteel alloy formed on the surface of the shell I and forms a further' copper steel valloy which penetrates into the surface of the bearing. This rolling process takes a certain length of time in practice from v3 to 6 minutes, in which time the necessary temperature must be maintained. The crucible is then removed from the furnace and violently agitated for approximately 20 seconds in order to thoroughly mix the molten lead and other metals with the molten copper of the bearing,- and the crucible then plunged into a cooling bath. This fixes or sets the liningJ which in its molten state after having been agitated in the case of bearings containing a great deal of lead is found to be in fact a lead emulsion, and the lead in the resultant lining metal presents a spheroid structure rather than a crystalline struc- .ture and hence can carry far greater loads than By actual test lead in a crystalline structure. my bearing has carried loads up to 4200 pounds as distinguished from 3000`p'ounds for bearings in which the lead has a crystalline structure. Also microphotographs of my bearing disclose a more favorable steelcopper alloy'on the surface of the shell than is possible were the molten copper which is separated from copper lead alloy not held at t'he constant necessary temperature in contactwith the steel aver the period of time above stated, that is, the period 3 to 6 minutes -ed as at I0 on its outer surface while cold with any known. hardening compound, and charged into a furnace of the muiiied type in which the flame does not contact directly with the snel. In this case whilethe crucible is being raised to the desired temperature and while the copper is soaking into the steel from the inside, the

hardening compound is soaking into the steel from outside, and kwhen the bearing is plunged into the cooling-'liquid to nx the copper lead or leadbronze emulsion on the inside the necessary chilling to harden the exterior of the shell simultaneously takes place giving a copper lead or bronze lead lining bearing. case-hardened on its exterior. Y

The same process using a reservoir shown in Fig. 3 in which the reservoir l: embraces the exterioreas well as the interior of the shell I,

can be used to simultaneously coat the inside 75.

and outside surfaces of the bearing, in case a copper lead or lead bronze surface is desired on both sufaces. In this case the sides of reservoir 6a: are extended to meet the plate 2:1: which is also extended beyond the side of shell l. In this case the linings on the interior and exterior of the shell I will be of the same alloy. If dierent alloys are desired two separate reservoirs must be used, one similar to reservoir 6 of Fig. 1 and the other similar to reservoir 6a: of Fig. 3, the latter reservoir, embracing the former.

The same process omitting the core can be used to centrifuge the bronze into the steel shell, in which case the bearing in its molten state is taken from the furnace and violently agitated as in the case of a gravity cast bearing so as to form the emulsion noted, and the crucible is put into a centrifugal machine and the copper lead or lead bronze alloy centrifuged into place, and immediately cooled by a vcooling spray. Hence I form a bearing surface of bronze or lead copper ed to the shell by alloying a part of the copper forming it directly to the shell.

It is to be understood that the invention is not limited to the constructions shown by way of example; and the process may be applied to objects of all forms, hollow or otherwise. Moreover, the non-oxidizing medium or atmosphere may be produced by other means, for example by a vacuum, and my invention includes, as novel commercial products, any steel objects coated superiicially, interiorly or exteriorly, with bronze or brass by the use of my method.

I claim:-

1. The method of making lead copper alloy bearings or the like which consists in cleaning a ferrous shell; hermetically sealing one end thereof; treating the shell with copper sulphate; introducing lead copper alloy lining material into the shell; hermetically sealing a reservoir at the other end of the shell; providing a vent; heating the shell to a temperature which will cause the copper sulphate to form an initial copper-iron alloy on the shell and melt the lining; up-ending the shell so that the reservoir is lowermost; collecting the molten lead constituent'of the alloy in the bottom of the reservoir; tilting the ,shell and rotating same slowly to cause the molten copper constituent to intimately contact with the copper-iron alloy on the shell for a suiiicient length of time to penetrate the surface thereof and increase the copper-iron bond; violently agitating the shell to thoroughly emulsify the molten lead and copper constituents; up-ending the shell to bring the emulsiied lining constituents into lining position in the shell while the lead constituent is in spheroidal form; and quickly chilling the shell to set the lining.

2. The method of making lead copper alloy bearings or the like which consists in cleaning a ferrous shell; hermetically sealing one end thereof; treating the shell with copper sulphate; introducing a volatile ux into the shell which will maintain a non-oxidizing atmosphere therein when heated; introducing lead copper alloy lining material into the shell; hermetically sealing a reservoir at the other end of the shell; providing a vent; heating the shell to a temperature which will volatilize the flux and will cause the copper sulphate to form an initial copperiron alloy on the shell and melt the lining; up

ending the shell so that the reservoir is lowermost; collecting the molten lead constituent of the alloy in the bottom of the reservoir; tilting the shell and rotating same slowly to cause the molten copper constituent to intimately contact with the copper-iron alloy on the shell for a sufficient length of time to penetrate the surface thereof and increase ,the copper-ironbond; vviolently agitating the shell to thoroughly emulsify the molten lead and copper constituents; upending the shell to bring the emulsifled lining constituents into lining position in the shell while the lead constituent is in spheroidal form; and quickly chilling the shell to set the ,lining material.

3. The method of making lead copper alloy bearings or the like which consists 1n pickling a ferrous shell; 'hermetically sealing one end thereof; treating the shell with copper sulphate to deposit copper thereon; introducing lead copper alloy lining material into the shell; hermetically sealing a reservoir at the other end of the shell; providing a vent; heating the shell to a temperature of about 2000 F. to cause the copper sulphate to form an initial copper-iron alloy on the shell and melt the lining; up-ending the shell so that the reservoir is lowermost; collecting the molten lead constituent of the alloy in the bottom of the reservoir; tilting the shell and rotating same slowly to cause the molten copper constituent to intimately contact with the copper-iron alloy on the shell for a suiiicient length of time to penetrate the surface thereof and increase the copper-iron bond; violently agitating the shell to thoroughly emulsify the molten lead and copper constituents; upending the shell to bring the emulsified lining material into lining position in the shell While the lead is in spheroidal form; and quickly chilling the shell to set the lining material.

4. The method of making lead copper alloy bearings or the like which consists in pickling a ferrous shell; hermetically sealing one end thereof; treating the shell with copper sulphate to deposit copper thereon; introducing a volatile flux into the shell which will maintain a non-oxidizingr atmosphere therein when heated; introducing lead copper alloy lining material into the shell; hermetically sealing a reservoir at the other end of the shell; providing a Vent; heating the shell to a temperature of about 2000 F. to volatilize the flux and to cause the copper sulphate to form an initial copper-iron alloy on the shell and melt the lining; up-ending the shell so that the reservoir is lowermost; collecting the molten lead constituent of the alloy in the bottom of the reservoir; tilting the shell and rotating same slowly to cause the molten copper constituent to intimately contact with the copper-iron alloy on the shell for a sufficient length of time to penetrate the surface thereof and increase the copper-iron bond; violently agitating the shell to thoroughly emulsify the molten lead and copper constituents; up-ending the shell to bring `the emulsiiied lining material into lining position in the shell while the lead constituent is in spheroidal form; and quickly chilling the shell to set the lining material.

HENRY LOWE BROWNBACK. 

